The present invention is concerned with certain heterocyclic organic compounds which can be referred to as substituted piperidines and acid addition salts thereof. In particular, this invention relates to physiologically active novel piperidine compounds which are particularly effective as antiarrhythmic and antiserotonin agents. It is also concerned with chemical intermediates useful in the preparation of the piperidine compounds. Other features of the invention are pharmaceutical compositions containing the piperidines as active ingredients and a therapeutic process for producing antiserotonin and antiarrhythmic effects in mammals by administration of them.
Agents which antagonize serotonin are of interest in experimental biology and in treatment of various physiological disorders such as migraine headache, serotonin producing tumors, toxemia in pregnancy, habitual abortion and management of various inflammatory and allergic reactions. Methysergide and lysergide are well known antiserotonin agents. Other serotonin antagonists which have been reported in the prior art literature on the subject are 2'-(3-dimethylaminopropylthio)cinnamanilide and related compounds disclosed by Krapcho, et al., J. Med. Chem., 6, 219 (1963); 7, 376 (1964); 9, 809 (1966); and 12, 164 (1969); and U.S. Pat. No. 3,192,213.
A number of structurally unrelated chemical substances have been employed in the treatment of cardiac arrhythmia; refer to A. Burger, Medicinal Chemistry, 3rd Edition, pages 1082-1085 (Wiley). One of the most important drugs in clinical treatment of disorders of cardiac rhythm is quinidine. Another chemical agent which has been used as an antiarrhythmic is the local anesthetic procaine amide. Still other antiarrhythmic agents are lidocaine, and diphenylhydantoin. None of these compounds are structurally related to the piperidines of the present invention.